[PATCH 6 of 8 "] compression: introduce an official `format.revlog-compression` option
Pierre-Yves David
pierre-yves.david at ens-lyon.org
Sun Mar 31 11:36:22 EDT 2019
# HG changeset patch
# User Pierre-Yves David <pierre-yves.david at octobus.net>
# Date 1553707614 -3600
# Wed Mar 27 18:26:54 2019 +0100
# Node ID 108e26fa0a97fe5342a1ce246cc4e4c185803454
# Parent 28701199a78bdbab36aa422be0b4681941433823
# EXP-Topic zstd-revlog
# Available At https://bitbucket.org/octobus/mercurial-devel/
# hg pull https://bitbucket.org/octobus/mercurial-devel/ -r 108e26fa0a97
compression: introduce an official `format.revlog-compression` option
This option superseed the `experiment.format.compression` option. The value
currently supported are zlib (default) and zstd (if Mercurial was compiled with
zstd support).
The option gained an explicite reference to `revlog` since this is the target
usage here. Different storage methods might requires different compression
strategies.
In our tests, using zstd give a significant CPU usage improvement (both
compression and decompressing) while keeping similar repository size.
Zstd as other interresting mode (dictionnaly, pre-text, etc…) that are probably
worth exploring. However, just play switching from zlib to zstd provide a large
benefit.
diff --git a/mercurial/configitems.py b/mercurial/configitems.py
--- a/mercurial/configitems.py
+++ b/mercurial/configitems.py
@@ -553,9 +553,6 @@ coreconfigitem('experimental', 'extended
coreconfigitem('experimental', 'extendedheader.similarity',
default=False,
)
-coreconfigitem('experimental', 'format.compression',
- default='zlib',
-)
coreconfigitem('experimental', 'graphshorten',
default=False,
)
@@ -684,6 +681,10 @@ coreconfigitem('format', 'obsstore-versi
coreconfigitem('format', 'sparse-revlog',
default=True,
)
+coreconfigitem('format', 'revlog-compression',
+ default='zlib',
+ alias=[('experimental', 'format.compression')]
+)
coreconfigitem('format', 'usefncache',
default=True,
)
diff --git a/mercurial/help/config.txt b/mercurial/help/config.txt
--- a/mercurial/help/config.txt
+++ b/mercurial/help/config.txt
@@ -866,6 +866,13 @@ https://www.mercurial-scm.org/wiki/Missi
Repositories with this on-disk format require Mercurial version 4.7
Enabled by default.
+``revlog-compression``
+ Compression algorithm used by revlog. Supported value are `zlib` and `zstd`.
+ The `zlib` engine is the historical default of Mercurial. `zstd` is a newer
+ format that is usually a net win over `zlib` operating faster at better
+ compression rate. Use `zstd` to reduce CPU usage.
+
+ On some system, Mercurial installation may lack `zstd` supports. Default is `zlib`.
``graph``
---------
diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -2920,10 +2920,10 @@ def newreporequirements(ui, createopts):
if ui.configbool('format', 'dotencode'):
requirements.add('dotencode')
- compengine = ui.config('experimental', 'format.compression')
+ compengine = ui.config('format', 'revlog-compression')
if compengine not in util.compengines:
raise error.Abort(_('compression engine %s defined by '
- 'experimental.format.compression not available') %
+ 'format.revlog-compression not available') %
compengine,
hint=_('run "hg debuginstall" to list available '
'compression engines'))
diff --git a/mercurial/upgrade.py b/mercurial/upgrade.py
--- a/mercurial/upgrade.py
+++ b/mercurial/upgrade.py
@@ -332,7 +332,7 @@ class compressionengine(formatvariant):
@classmethod
def fromconfig(cls, repo):
- return repo.ui.config('experimental', 'format.compression')
+ return repo.ui.config('format', 'revlog-compression')
@registerformatvariant
class compressionlevel(formatvariant):
diff --git a/tests/test-repo-compengines.t b/tests/test-repo-compengines.t
--- a/tests/test-repo-compengines.t
+++ b/tests/test-repo-compengines.t
@@ -21,8 +21,8 @@ A new repository uses zlib storage, whic
Unknown compression engine to format.compression aborts
- $ hg --config experimental.format.compression=unknown init unknown
- abort: compression engine unknown defined by experimental.format.compression not available
+ $ hg --config format.revlog-compression=unknown init unknown
+ abort: compression engine unknown defined by format.revlog-compression not available
(run "hg debuginstall" to list available compression engines)
[255]
@@ -40,7 +40,7 @@ A requirement specifying an unknown comp
#if zstd
- $ hg --config experimental.format.compression=zstd init zstd
+ $ hg --config format.revlog-compression=zstd init zstd
$ cd zstd
$ cat .hg/requires
dotencode
@@ -66,7 +66,7 @@ with that engine or a requirement
$ cd default
$ touch bar
- $ hg --config experimental.format.compression=zstd -q commit -A -m 'add bar with a lot of repeated repeated repeated text'
+ $ hg --config format.revlog-compression=zstd -q commit -A -m 'add bar with a lot of repeated repeated repeated text'
$ cat .hg/requires
dotencode
@@ -141,13 +141,13 @@ Test error cases
checking zstd options
=====================
- $ hg init zstd-level-default --config experimental.format.compression=zstd
- $ hg init zstd-level-1 --config experimental.format.compression=zstd
+ $ hg init zstd-level-default --config format.revlog-compression=zstd
+ $ hg init zstd-level-1 --config format.revlog-compression=zstd
$ cat << EOF >> zstd-level-1/.hg/hgrc
> [storage]
> revlog.zstd.level=1
> EOF
- $ hg init zstd-level-22 --config experimental.format.compression=zstd
+ $ hg init zstd-level-22 --config format.revlog-compression=zstd
$ cat << EOF >> zstd-level-22/.hg/hgrc
> [storage]
> revlog.zstd.level=22
@@ -172,7 +172,7 @@ checking zstd options
Test error cases
- $ hg init zstd-level-invalid --config experimental.format.compression=zstd
+ $ hg init zstd-level-invalid --config format.revlog-compression=zstd
$ cat << EOF >> zstd-level-invalid/.hg/hgrc
> [storage]
> revlog.zstd.level=foobar
@@ -182,7 +182,7 @@ Test error cases
abort: storage.revlog.zstd.level is not a valid integer ('foobar')
[255]
- $ hg init zstd-level-out-of-range --config experimental.format.compression=zstd
+ $ hg init zstd-level-out-of-range --config format.revlog-compression=zstd
$ cat << EOF >> zstd-level-out-of-range/.hg/hgrc
> [storage]
> revlog.zstd.level=42
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